The magnetic storage medium in a conventional disk drive may be divided into several storage areas. One of these storage areas known as the User Area and it is set aside for normal storage use by the computer user. The user is normally allowed unrestricted access to this User Area through the operating system of the host device via a standard interface such as Advanced Technology Attachment (ATA) or Small Computer System Interface (SCSI), and employing addressing schemes such as Logical Block Addresses (LBA's). When user access control is needed, password protection is often used to enable or disable read and/or write operations to the User Area. However, read and/or write access authorization to the User Area alone does not provide adequate security protection because no integrity verification or origin authentication is performed on the transmitted data. In addition, the scope of password-enabled read/write authorization is often too broad since the authorization usually applies to the entire User Area or its partitions. Proposals for a specific authorization protocol that applies to individual data blocks have been made but they rely on authorization or authentication to be tested for each block transfer. This approach reduces the speed of the read/write operation, especially when the operation involves a relatively large data file.
The same disk drive may also contain another storage area that is created by the disk drive vendor and is referred to as the Hidden System Area. This storage area is unseen by and inaccessible to the user during normal operation. The Hidden System Area is usually fixed in size, less than one megabyte, and used for keeping system data such as the firmware of the disk drive.
In addition to the magnetic storage medium, a conventional disk drive uses a temporary data buffer in the form of volatile RAM in the host system (e.g. a server). This RAM buffer is used to cache read and write data and to perform verification and authentication operations on the cached data. A disadvantage of caching data to a volatile RAM buffer is that the data set may be too large for the data buffer. This approach imposes an artificial limit on the net data size. One method to overcome the size limitation issue is to increase the volatile RAM buffer size. However, volatile RAM buffer memory often uses relatively more expensive memory chips. Therefore, adding more memory chips to increase the buffer size will add cost to the disk drive. Another method is to create a special buffer storage area on the storage medium and to perform data verification and authentication on the temporarily stored data. Unfortunately, a specialized buffer storage area requires significant resources from the operating system to create, manage and protect. The foregoing drawbacks in the prior art are exacerbated when handling transfers of bulk volume of data from one storage location to another, such as between network attached storage (NAS) devices, where high speed broadband data transfer would meet “last mile” bottleneck in data handling at the destination or source drives.
What is needed is a magnetic disk drive system, and method, which allow bulk data transfers with high-speed data verification and authentication operations requiring minimal operating system resources.